'From Squeak2.8 of 13 June 2000 [latest update: #2359] on 28 November 2000 at 6:54:46 am'!
EllipseMorph subclass: #SwingMorph
	instanceVariableNames: 'position velocity '
	classVariableNames: ''
	poolDictionaries: ''
	category: 'Morphic-Demo'!

!SwingMorph methodsFor: 'as yet unclassified' stamp: 'ward 11/28/2000 00:00'!
initialize
	super initialize.
	velocity _ 0@0.
	position _ 0@0! !

!SwingMorph methodsFor: 'as yet unclassified' stamp: 'ward 11/28/2000 01:07'!
step

	| mags acceleration delta |
	super step.
	mags _ owner submorphs select: 
		[:each | each class == EllipseMorph].
	acceleration _ mags inject: 0@0 into: 
		[:sum :each |  
		delta _ each position - position. 
		sum + (delta / (delta r squared + 2))].
	acceleration _ velocity * -0.0001 + acceleration.
	velocity _ velocity + (acceleration * 10) .  
	position _ position + velocity.
	self position: position rounded! !

!SwingMorph methodsFor: 'as yet unclassified' stamp: 'ward 11/28/2000 00:04'!
stepTime
	"As fast as possible."

	^ 0
! !